Lancia Beta Forum

Technical stuff => Fuel System VX => Topic started by: markwast on March 07, 2011, 05:16:02 PM



Title: Fuel blow back through carb
Post by: markwast on March 07, 2011, 05:16:02 PM
Hi all,
Got the spark problem sorted out eventually and now to the next problem...

When turning over the engine , it fires up eventually but soon dies. I think that there is too much fuel going in but blows back out through the carb, also exhaust smoke can be blown out through the carb and from the cream coloured unit sitting on top of the supercharger.

Could it be that it is over-fuelling ? thinking maybe the fuel regulater is duff.

Also think that as the engine has been laid ideal for some 5+ years, think that valves are shot.

If i cant get the car going , think it will be put to rest............


Title: Re: Fuel blow back through carb
Post by: Ammy on March 07, 2011, 08:26:19 PM
Hi Mark,
Don't want to worry you but -------  I had a similar problem with my spyder some time back and it turned out to be No1 exhaust cam had worn away completely.  The camshaft was completely round and therefore the exhaust couldn't get away but came back thro. the inlet when it opened. Made a peculiar noise,  particularly when accelerating as well.
Hope it's not that.

Ammy


Title: Re: Fuel blow back through carb
Post by: WestonE on March 07, 2011, 11:05:21 PM
Mark

Do a compression test first to check valves/ cam timing and rings are OK. NB oil down the bores will show an improvement pointing to the rings not seating (corroded to pistons or bore damage).  I have seen low compression before from the exhaust cam pulley fitted to the inlet cam and vice versa. Hours were spent trying everything possible before the compression test.  Have you checked the base static timing is correct?
Are the plugs wet across the board ie are you getting a consistent spark or is it flooding? Try easy start down the chokes of the carb with clean dry plugs if it suddenly runs cleanly you have a fuel supply/ pressure problem. 

Hope it helps
PS visual inspection of the cam lobes for heavy wear is worth checking I had one lobe worn to a point on the inlet cam on a VX engine through oil starvation at a guess.

Eric


Title: Re: Fuel blow back through carb
Post by: JoeBeta on March 08, 2011, 10:05:48 AM
Don't like to under complicate things, (don't want to insult anyone) 
I only have the 1.6 coupe, but when I get petrol blow back through the carb it is usually a timing problem????  Sorry if you have already tried this?? but I guess best to check the basic things first..  cheers Joe